Calyx
Calyx provides a simple API for generating text with declarative recursive grammars.
Install
Command Line
gem install calyx
Gemfile
gem 'calyx'
Usage
Require the library and inherit from Calyx::Grammar
to construct a set of rules to generate a text. All grammars require a start
rule, which specifies the starting point for generating the text structure.
require 'calyx'
class HelloWorld < Calyx::Grammar
start 'Hello world.'
end
To generate the text itself, initialize the object and call the generate
method.
hello = HelloWorld.new
hello.generate
# > "Hello world."
Obviously, this hardcoded sentence isn’t very interesting by itself. Possible variations can be added to the text using the rule
constructor to provide a named set of text strings and the rule delimiter syntax ({}
) within the text strings to substitute the generated content of the rule.
class HelloWorld < Calyx::Grammar
start '{greeting} world.'
rule :greeting, 'Hello', 'Hi', 'Hey', 'Yo'
end
hello = HelloWorld.new
hello.generate
# > "Hi world."
hello.generate
# > "Hello world."
hello.generate
# > "Yo world."
Rules are recursive. They can be arbitrarily nested and connected to generate larger and more complex texts.
class HelloWorld < Calyx::Grammar
start '{greeting} {world_phrase}.'
rule :greeting, 'Hello', 'Hi', 'Hey', 'Yo'
rule :world_phrase, '{happy_adj} world', '{sad_adj} world', 'world'
rule :happy_adj, 'wonderful', 'amazing', 'bright', 'beautiful'
rule :sad_adj, 'cruel', 'miserable'
end
Nesting and hierarchy can be manipulated to balance consistency with variation. The exact same word atoms can be combined in different ways to produce strikingly different resulting texts.
module HelloWorld
Sentiment < Calyx::Grammar
start '{happy_phrase}', '{sad_phrase}'
rule :happy_phrase, '{happy_greeting} {happy_adj} world.'
rule :happy_greeting, 'Hello', 'Hi', 'Hey', 'Yo'
rule :happy_adj, 'wonderful', 'amazing', 'bright', 'beautiful'
rule :sad_phrase, '{sad_greeting} {sad_adj} world.'
rule :sad_greeting, 'Goodbye', 'So long', 'Farewell'
rule :sad_adj, 'cruel', 'miserable'
end
Mixed < Calyx::Grammar
start '{greeting} {adj} world.'
rule :greeting, 'Hello', 'Hi', 'Hey', 'Yo', 'Goodbye', 'So long', 'Farewell'
rule :adj, 'wonderful', 'amazing', 'bright', 'beautiful', 'cruel', 'miserable'
end
end
License
Calyx is open source and provided under the terms of the MIT license. Copyright (c) 2015 Mark Rickerby
See the LICENSE
file included with the project distribution for more information.